This invention relates generally to gas turbine engines, and more particularly, to a gas turbine engine rotor blade and a method of fabricating the same.
Gas turbine engines typically include high and low pressure compressors, a combustor, and at least one turbine. The compressors compress air which is mixed with fuel and channeled to the combustor. The mixture is then ignited for generating hot combustion gases, and the combustion gases are channeled to the turbine which extracts energy from the combustion gases for powering the compressor, as well as producing useful work to propel an aircraft in flight or to power a load, such as an electrical generator.
At least one known gas turbine fan assembly includes a plurality of rotor blades each having an airfoil that is fabricated utilizing a metallic material, such as titanium for example, and a composite material that is bonded to the surface of the airfoil. More specifically, the known airfoil is fabricated such that the composite material is laid up as individual unidirectional plies of material on the surface of the airfoil. However, for relatively small airfoils the titanium may become quite large and thus dominate the structural load path. As such, instead of the composite carrying the titanium, the titanium is carrying the composite.
Moreover, when the gas turbine engine operates in various conditions, foreign objects may be ingested into the engine. More specifically, if a foreign object strikes the airfoil, since the composite material is only bonded to the external surface of the airfoil, a portion of the composite material may be liberated from the airfoil and thus enter the engine flow path resulting in further foreign object damage to the gas turbine engine.